Wired circuit board and production method thereof

ABSTRACT

An elongated wired circuit board including a plurality of wires arranged in parallel, wherein the plurality of wires each includes a first linear portion extending in a first linear direction, a second linear portion extending in a second linear direction, and a connection portion, the connection portion includes a first side, a second side, a third side, and a fourth side, length y1 and length S satisfy 0&lt;y1&lt;S, length y1 extending from the first corner portion reaching the first widthwise other end edge of the first linear portion, and length S extending from the first widthwise other end edge of the first linear portion of one wire, and the predetermined angle θ satisfies 0&lt;θ&lt;1 deg.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional of U.S. patent application Ser.No. 16/464,422, filed on May 28, 2019, which 35 U.S.C. 371 NationalStage Entry of PCT/JP2017/039980, filed on Nov. 6, 2017, which claimspriority from Japanese Patent Application No. 2016-232481, filed on Nov.30, 2016, the contents of all of which are herein incorporated byreference in their entirety.

TECHNICAL FIELD

The present invention relates to a wired circuit board and a productionmethod thereof. In particular, the present invention relates to anelongated flexible wired circuit board and a production method thereof.

BACKGROUND ART

Conventionally, examination or treatment has been conducted using acatheter on which an electronic component such as a pressure sensor,temperature sensor, and heating element are mounted, and inserting thecatheter into the patient's body. Such a catheter contains an elongatedflexible wired circuit board inside the catheter tube, the elongatedflexible wired circuit board extending from the front end reaching therear end of the catheter tube. The conductive pattern formed on theelongated flexible wired circuit board includes, at its front end, aterminal for mounting the electronic components, and at its rear end, aterminal for connecting with external components (monitor or powersource, etc.), and an elongated wire for connecting these terminals.

Meanwhile, the conductive pattern is formed by various methods such assubtractive method and semiadditive method. In these methods, a resistis formed on the entire surface of the metal film, a photomask matchingthe wire is disposed, the resist is exposed to light and developed, andthereafter, wires are formed.

However, the length of the wires of the elongated flexible wired circuitboard used for catheters is at least 600 mm or more, and sometimes morethan 2000 mm. On the other hand, the photomask has a general size ofabout 250 mm×250 mm Therefore, one set of exposure and developmentcannot form the target wires. Thus, patent document 1 proposes a methodin which exposure and development are conducted a plurality of times(ref: patent document 1).

Patent document 1 discloses a production method of a flexible wiredcircuit board with a subtractive method. To be specific, the productionmethod of patent document 1 includes, a step of forming a metal layer onan insulating layer substrate, a step of forming a resist layer on themetal layer, a step in which a photomask having an opening with apredetermined length and equal width at both end portions is disposed ina longitudinal direction of the insulating substrate so that the endportions of the opening overlap one after another and the resist layeris exposed to light repeatedly, a step of developing the resist pattern,and a step of forming wires by removing the metal layer where the resistpattern is not formed by etching.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Unexamined Patent Publication No.    2005-286207

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

Meanwhile, to decrease burden on patients, decrease in the diameter sizeof the catheter, and extra fine wires have been demanded.

However, when extra fine, elongated plural wires are tried to be formedusing the production method of patent document 1, there aredisadvantages in that at the position where the photomask is overlaid,the end portions of the opening tend to displace in a directionorthogonal to longitudinal direction or oblique direction. Therefore, atthe overlaid position, one wire may be dislocated relative to the otherwire in the width direction or oblique direction, and as a result, itmay cause disconnection or short circuit with adjacent wires. That is,connection reliability is poor.

Furthermore, when dislocation of one wire to the other wire in the widthdirection is to be completely eliminated, the photomask has to bedisposed with high accuracy. Therefore, productivity is poor.

The present invention provides an elongated wired circuit board withexcellent connection reliability and productivity, and a productionmethod thereof.

Means for Solving the Problem

The present invention [1] includes an elongated wired circuit boardincluding a plurality of wires arranged in parallel, wherein theplurality of wires each includes

a first linear portion extending in a first linear direction,

a second linear portion having the same width as that of the firstlinear portion, disposed at one side in the first linear direction ofthe first linear portion, and extending in a second linear direction soas to have a predetermined angle θ relative to the first linear portion,and

a connection portion disposed between the first linear portion and thesecond linear portion, being continuous with the first linear portionand the second linear portion, and having a width broader than the firstlinear portion;

the connection portion includes a first side further extending from afirst widthwise one end edge orthogonal to the first linear direction ofthe first linear portion along the first linear direction,

a second side further extending from the second widthwise other end edgeorthogonal to the second linear direction of the second linear portionalong the second linear direction,

a third side connecting the first side with the second linear directionend edge of the second widthwise one end edge of the second linearportion and extending along the first-crossing direction crossing thefirst linear direction and the second linear direction, and

a fourth side connecting the second side with the first linear directionend edge of the first widthwise other end edge of the first linearportion, and extending along a second-crossing direction crossing thefirst linear direction and the second linear direction;

length y₁ and length S satisfy the relationship of 0<y₁<S,

length y₁ extending from a first corner portion formed with the secondside and the fourth side along the first width direction and reachingthe first widthwise other end edge of the first linear portion and

length S extending from the first widthwise other end edge of the firstlinear portion of one wire to a first widthwise one end edge of thefirst linear portion of the other wire along the first width directionin two wires adjacent to each other, and the predetermined angle θsatisfies the relationship of 0<θ<1 deg.

With such a wired circuit board, the length y₁ from the first cornerportion to the first linear portion and length S from the first linearportion of one wire to the first linear portion of the other wire (wireinterval) satisfy 0<y₁<S. That is, at the connection portion between thefirst linear portion and the second linear portion, widthwisedislocation between the first linear portion and the second linearportion is shorter than the wire interval S. Also, the predeterminedangle θ satisfies θ<1 deg. That is, the angle formed with the firstlinear portion and the second linear portion is small. Thus, linearitycan be secured even when the wire is elongated, short circuit betweenadjacent wires can be suppressed, and connection reliability isexcellent.

Furthermore, the predetermined angle θ satisfies θ<0. That is, the angleformed with the linear direction of the first linear portion and thelinear direction of the second linear portion is small. Therefore,strict adjustment for the angle formed with the first linear portion andthe second linear portion is unnecessary, and thus productivity isexcellent.

The present invention [2] includes the wired circuit board described in[1], wherein the length D₁ of the first side and the length S satisfythe relationship of D₁×tan θ+y₁<S.

With such a wired circuit board, at the connection portion between thefirst linear portion and the second linear portion, short circuit can besuppressed more reliably.

The present invention [3] includes the wired circuit board of [1] or[2], wherein the length D₁ and a length W of the first width directionof the first linear portion satisfy the relationship of W≤D₁.

With such a wired circuit board, at the connection portion, thelongitudinal length of the connection portion is sufficiently long.Therefore, the electric signal easily flows in the elongated directionwhile widthwise flow is suppressed at the connection portion. Thus,propagation of electric signals is excellent.

The present invention [4] includes an elongated wired circuit boardincluding a plurality of wires arranged in parallel,

wherein the plurality of wires each includes

a first linear portion extending in a first linear direction,

a second linear portion having the same width as that of the firstlinear portion, disposed at one side in the first linear direction ofthe first linear portion, and extending in a second linear direction soas to have a predetermined angle θ relative to the first linear portion,and

a connection portion disposed between the first linear portion and thesecond linear portion, being continuous with the first linear portionand the second linear portion, and having a width narrower than that ofthe first linear portion;

the connection portion includes a first side further extending from afirst widthwise one end edge orthogonal to the first linear direction ofthe first linear portion along the first linear direction,

a second side further extending from the second widthwise other end edgeorthogonal to the second linear direction of the second linear portionalong the second linear direction, and

the second linear portion includes a third side connecting the firstside with the second widthwise one end edge of the second linearportion, and extending along the first-crossing direction crossing thefirst linear direction and the second linear direction, and

the first linear portion includes a fourth side connecting the secondside with the first widthwise other end edge of the first linearportion, and extending along the second-crossing direction crossing thefirst linear direction and the second linear direction,

length y₂ and length W satisfy the relationship of 0<y₂<W, the length y₂extending from a second corner portion formed with the first widthwiseone end edge of the second linear portion and the third side andreaching the first side along the first width direction, and the lengthW being the first width of the first linear portion, and thepredetermined angle θ satisfy the relationship of 0<θ<1 deg.

With such a wired circuit board, length y₂ from the second cornerportion to the first side, and the length W of the first width of thefirst linear portion satisfy the relationship of 0<y₂<W. That is, at theconnection portion between the first linear portion and the secondlinear portion, widthwise dislocation between the first linear portionand the second linear portion is shorter than the width W of the firstlinear portion. Also, the predetermined angle θ satisfies θ<1 deg.Therefore, the angle formed with the first linear portion and the secondlinear portion is small. As a result, linearity can be secured even whenthe wire is elongated, while disconnection of the connection portion canbe suppressed in the wires continuous in front-rear direction, andconnection reliability is excellent.

Also, the predetermined angle θ satisfies θ<0. That is, the angle formedwith the linear direction of the first linear portion and the lineardirection of the second linear portion is small. Thus, strict adjustmentfor the angle formed with the first linear portion and the second linearportion is unnecessary, and therefore productivity is excellent.

The present invention [5] includes the wired circuit board of [4],wherein the first side length D₁ and the first width W satisfy therelationship of D₁×tan θ+y₂′<W (where y₂′ represents a length from thethird corner portion formed with the second side and the fourth side tothe first widthwise other end edge of the first linear portion along thefirst width direction).

With such a wired circuit board, at the connection portion between thefirst linear portion and the second linear portion, disconnection can besuppressed even more reliably.

The present invention [6] includes the wired circuit board of any one of[1] to [5], wherein the wire has a wire length of 600 mm or more.

Such a wired circuit board can be suitably used as a wired circuit boardfor catheters.

The present invention [7] includes the wired circuit board of any one ofthe [1] to [6], including a first insulating layer, a conductive patternprovided at one surface in the thickness direction of the firstinsulating layer, and a second insulating layer provided at one surfacein the thickness direction of the conductive pattern, wherein theconductive pattern includes the wire.

With such a wired circuit board, the first insulating layer, wire, andsecond insulating layer are disposed in this order so as to contact witheach other, and therefore no adhesive layer is necessary. Therefore,moisture and heat resistance is excellent, and the thickness can bedecreased.

The present invention [8] includes a method for producing an elongatedwired circuit board including a plurality of wires arranged in parallel,the method including the steps of: a first step, in which an insulatinglayer is prepared, and a second step, in which the plurality of wiresarranged in parallel are formed on the surface of the insulating layer,wherein the second step includes a step (1), in which a metal thin filmis formed on the surface of the insulating layer, a step (2), in which aphoto resist is formed on the surface of the metal thin film, a step(3), in which a photomask is disposed on the surface of the photo resistso as to face the photo resist, the photomask having a lighttransmission portion formed as a plurality of linear patterns arrangedin parallel so as to match the plurality of the wires, and the photoresist is exposed to light through the photomask, and a step (4), inwhich the photo resist facing the light transmission portion is removedto expose the metal thin film by development, a step (5), in which theplurality of wires are formed on the surface of the exposed metal thinfilm by plating, and a step (6), in which the remaining photo resist,and the metal thin film facing the remaining photo resist are removed,

wherein the second step includes a step of conducting the step (3) aplurality of times so that a connection portion having a width broaderthan the linear pattern is formed in each wire by shifting the photomaskrelative to the photo resist in the first linear direction, and in theeach step of the plurality of steps, the photomask is disposed so thatthe linear pattern of the light transmission portion of the followingphotomask has a predetermined angle θ (0<θ<1 deg) relative to the linearpattern of the light transmission portion of the previous photomask.

With such a method for producing a wired circuit board, a wired circuitboard with connection reliability with suppressed short circuit can beproduced with excellent productivity.

The present invention [9] includes a method for producing an elongatedwired circuit board including a plurality of wires arranged in parallel,the method including the steps of: a first step, in which an insulatinglayer is prepared, and a second step, in which the plurality of wiresarranged in parallel are formed on the surface of the insulating layer,wherein the second step includes a step (1), in which a metal thin filmis formed on the surface of the insulating layer; a step (2), in which aphoto resist is formed on the surface of the metal thin film; a step(3), in which a photomask is disposed on the surface of the photo resistso as to face the photo resist, and the photo resist is exposed to lightthrough the photomask, the photomask having a shield portion formed as aplurality of linear patterns arranged in parallel so as to match theplurality of the wires; a step (4), in which the photo resist facing theshield portion is removed to expose the metal thin film by development;a step (5), in which the plurality of wires are formed on the surface ofthe exposed metal thin film by plating; and a step (6), in which theremaining photo resist and the metal thin film facing the remainingphoto resist are removed; wherein the second step includes a step ofconducting the step (3) a plurality of times so that a connectionportion having a width narrower than a linear pattern is formed in eachwire by shifting the photomask relative to the photo resist in the firstlinear direction, and in the each step of the plurality of steps, thephotomask is disposed so that the linear pattern of the shield portionof the following photomask has a predetermined angle θ (0<θ<1 deg)relative to the linear pattern of the shield portion of the previousphotomask.

With such a method for producing a wired circuit board, a wired circuitboard with connection reliability with suppressed disconnection can beproduced with excellent productivity.

Effects of the Invention

The wired circuit board produced by the production method of the presentinvention has excellent connection reliability and productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-FIG. 1B show a first embodiment of the wired circuit board ofthe present invention, FIG. 1A showing a plan view, and FIG. 1B showinga cross sectional view along A-A of FIG. 1A.

FIG. 2 shows a partial enlargement of the wire portion shown in FIG. 1A.

FIG. 3 shows a partial enlargement of the connection portion at thefirst region and the second region shown in FIG. 2.

FIG. 4 shows a partial enlargement of the connection portion at thesecond region and the third region shown in FIG. 2.

FIG. 5A-FIG. 5I show process diagram of the method for producing a wiredcircuit board shown in FIG. 1A, FIG. 5A illustrating a step of preparingan insulating base layer, FIG. 5B illustrating a step of forming a metalthin film, FIG. 5C illustrating a step of forming a photo resist, FIG.5D illustrating a step of exposing the photo resist to light, FIG. 5Eillustrating a step of developing the photo resist, FIG. 5F illustratinga step of forming wires, FIG. 5G illustrating a step of removing thephoto resist, FIG. 5H illustrating a step of removing the metal thinfilm, and FIG. 5I illustrating a step of forming an insulating coverlayer.

FIG. 6 shows a plan view of the photomask used in the production processshown in FIG. 5.

FIG. 7 shows a photomask placement.

FIG. 8A-FIG. 8B show the catheter including the wired circuit boardshown in FIG. 1A, FIG. 8A illustrating a side cross sectional view alongthe front-rear direction, and FIG. 8B illustrating a cross sectionalview along A-A in FIG. 8A.

FIG. 9 shows an enlarged plan view of the wired circuit board in amodified example (embodiment in which the rear side is the first linearportion) of the first embodiment.

FIG. 10 shows an enlarged plan view of the wired circuit board in amodified example (embodiment in which the first corner portion and thefourth corner portion form an obtuse angle) of the first embodiment.

FIG. 11 shows a plan view of the wire portion of the wired circuit boardin the second embodiment of the present invention.

FIG. 12 shows a partial enlargement view of the wire portion shown inFIG. 11, and a photomask placement.

FIG. 13 shows a partial enlargement view of the connection portion inthe first region and the second region shown in FIG. 12.

FIG. 14 shows a partial enlargement of the connection portion in thesecond region and the third region shown in FIG. 12.

FIG. 15A-FIG. 15I show process diagrams of the method for producing awired circuit board shown in FIG. 11, FIG. 15A illustrating a step ofpreparing an insulating base layer, FIG. 15B illustrating a step offorming a metal thin film, FIG. 15C illustrating a step of forming aphoto resist, FIG. 15D illustrating a step of exposing the photo resistto light, FIG. 15E illustrating a step of developing the photo resist,FIG. 15F illustrating a step of forming wires, FIG. 15G illustrating astep of removing the photo resist, FIG. 15H illustrating a step ofremoving a metal thin film, and FIG. 15I illustrating a step of formingan insulating cover layer.

FIG. 16 shows a plan view of the photomask used in the productionprocess shown in FIG. 15.

FIG. 17 shows an enlarged plan view of the wired circuit board in amodified example of the second embodiment (embodiment in which the rearside is the first linear portion).

FIG. 18 shows an enlarged plan view of the wired circuit board in amodified example (embodiment in which the second corner portion and thethird corner portion form an obtuse angle) of the first embodiment.

DESCRIPTION OF THE EMBODIMENTS

In FIG. 1A, the left-right direction on the sheet of paper is front-reardirection (FPC longitudinal direction), left side on the sheet of paperis front side (one side in the longitudinal direction), and the rightside on the sheet of paper is rear side (the other side in longitudinaldirection). Up-down direction on the sheet of paper is left-rightdirection (FPC width direction, orthogonal direction orthogonal tofront-rear direction), the lower side on the sheet of paper is rightside (one side in FPC width direction), and the upper side on the sheetof paper is left side (the other side in FPC width direction). Paperthickness direction on the sheet of paper is up-down direction(thickness direction, orthogonal direction orthogonal to front-reardirection and left-right direction), the near side on the sheet of paperis upper side (one side in thickness direction), and the far side on thesheet of paper is lower side (the other side in thickness direction). Tobe specific, the directions are in accordance with the direction arrowsin the figures.

First Embodiment

A wired circuit board 1 in the first embodiment of the wired circuitboard of the present invention is described with reference to FIG. 1A toFIG. 4.

The wired circuit board 1 is a flexible wired circuit board (FPC)elongated in front-rear direction, and as shown in FIG. 1A, it is formedinto a flat plate shape (sheet shape) extending in front-rear direction.The wired circuit board 1 includes, as shown in FIG. 1B, an insulatingbase layer 2 as the first insulating layer, a conductive pattern 3formed on the insulating base layer 2, and an insulating cover layer 4as the second insulating layer formed on the conductive pattern 3.

The insulating base layer 2 is formed into a flat plate shape (sheetshape) extending in front-rear direction, and has a contour of the wiredcircuit board 1.

An electronic component-mount portion 6 for mounting an electroniccomponent 5 (described later) is defined at the front end of theinsulating base layer 2.

The insulating base layer 2 is formed from an insulating material.Examples of the insulating material include synthetic resins such aspolyimide resin, polyamide-imide resin, acrylic resin, polyether nitrileresin, polyether sulfone resin, polyethylene terephthalate resin,polyethylenenaphthalate resin, and polyvinyl chloride resin. Preferably,the insulating base layer 2 is formed from polyimide resin.

The insulating base layer 2 has a thickness of, for example, 3 μm ormore, preferably 5 μm or more, and for example, 50 μm or less,preferably 30 μm or less.

The conductive pattern 3 is formed on the upper face (one side in thethickness direction) of the insulating base layer 2. The conductivepattern 3 includes, as shown in FIG. 1A, an electronic componentterminal portion 7, external component terminal portion 8, and wireportion 9.

The electronic component terminal portion 7 is a terminal forelectrically connecting with an electronic component 5 (describedlater). The electronic component terminal portion 7 is disposed behindthe electronic component-mount portion 6 at the front end of theinsulating base layer 2. The electronic component terminal portion 7includes a plurality of (5) electronic component terminals 10.

The plurality of electronic component terminals 10 are disposed inspaced apart relation from each other in left-right direction. Theelectronic component terminal 10 is formed into a generally rectangularshape when viewed from the top. The electronic component terminal 10 hasa width (left-right direction length) larger than the width of the wire12 described later (that is, first width W of first linear portion).

The external component terminal portion 8 is a terminal for electricallyconnecting with an external component (not shown). The externalcomponent terminal portion 8 is disposed at the rear end portion of theinsulating base layer 2, and includes a plurality of (5) externalcomponent terminals 11 corresponding to the plurality of (5) electroniccomponent terminals 10.

The plurality of external component terminals 11 are disposed in spacedapart relation from each other in left-right direction. The externalcomponent terminal 11 is formed into a generally rectangular shape whenviewed from the top. The external component terminal 11 has a width(left-right direction length) larger than the width of the wire 12described later (that is, first width W of first linear portion).

The wire portion 9 is disposed between the electronic component terminalportion 7 and the external component terminal portion 8 so as to connectthem. The wire portion 9 includes a plurality of (5) wires 12 (12 a, 12b, 12 c, 12 d, 12 e) in correspondence with the plurality of (5)electronic component terminal portions 7 and a plurality of (5) externalcomponent terminal portions 8.

The plurality of wires 12 are formed so as to extend in front-reardirection. The wire 12 is integrally formed with the electroniccomponent terminal 10 and the external component terminal 11 so that thefront end edge thereof is continuous with the rear end edge of theelectronic component terminal 10, and their end edge is continuous withthe front end edge of the external component terminal 11.

The wire portion 9 includes a pattern produced by conducting exposure tolight and development a plural times using a wire-photomask 40(described later), in the production method as described later withreference to FIG. 2 and FIG. 7. That is, in the wire portion 9, a singlepattern region in correspondence with a pattern of one set of exposureto light and development (first region, second region, third region, ⋅ ⋅⋅ individually) of the wire-photomask 40 continues a plural times infront-rear direction, with a partial overlapping at both ends infront-rear direction. To be specific, the wire portion 9 includes aparallelly arranged linear portion 20 corresponding to the centerportion in front-rear direction of the light transmission portion 41(described later), and a parallelly arranged connection portion 30corresponding to the overlapping region 43 (described later) of thewire-photomask 40. The wire portion 9 includes a plurality of parallellyarranged linear portions 20 and a plurality of parallelly arrangedconnection portions 30. That is, the wire portion 9 is formed so thatthe parallelly arranged linear portion 20 and the parallelly arrangedconnection portion 30 are alternately continuous in front-reardirection.

As shown in FIG. 2, the parallelly arranged linear portion 20 eachincludes a plurality of (5) linear portions 21 (21 a, 21 b, 21 c, 21 d,21 e) disposed in left-right direction with equal interval therebetween.The plurality of linear portions 21 are formed into a linear patterneach having a predetermined width and extending linearly. The pluralityof linear portions 21 (21 a, 21 b, 21 c, 21 d, 21 e) have substantiallythe same shape.

The parallelly arranged connection portion 30 each includes a pluralityof (5) connection portions 31 (31 a, 31 b, 31 c, 31 d, 31 e) disposed inleft-right direction with an equal interval therebetween. The pluralityof connection portions 31 have substantially the same shape, and theirwidths are formed to be wider than that of the linear portion 21 (21 a,21 b, 21 c, 21 d, 21 e).

Next, description is given with reference to FIG. 3 as to one linearportion (hereinafter referred to as first linear portion 22), oneconnection portion 31 continuous to the rear side of the first linearportion 22, and another linear portion continuous to the rear side ofthe one connection portion 31 (hereinafter referred to as second linearportion 23), using the wire 12 (12 a) at the rightmost in the firstregion (m-th region) and the second region (m-th+1 region) as anexample.

The first linear portion 22 is formed into a linear pattern extendinglinearly in the first linear direction. The width W of the first linearportion 22 (first width in the first width direction orthogonal to thefirst linear direction) is substantially the same from the front end tothe rear end of the first linear portion 22. The first linear portion 22has a width W of, for example, 10 μm or more, preferably 15 μm or more,and for example, 300 μm or less, preferably 150 μm or less.

The second linear portion 23 is formed into a linear pattern extendinglinearly in the second linear direction. The width of the second linearportion 23 (second orthogonal length in second width directionorthogonal to the second linear direction) is the same as the width W ofthe first linear portion 22. The width of the second linear portion 23is substantially the same from the front end to the rear end of thesecond linear portion 23. The second linear portion 23 has asubstantially the same shape as that of the first linear portion 22,except for the direction the second linear portion 23 extends.

The first linear direction and the second linear direction form an angleθ (0<θ<1 deg, preferably 0.01 deg≤θ≤0.95 deg, more preferably 0.05deg≤θ≤0.95 deg). To be specific, the first widthwise one end edge 24 aof the first linear portion 22 and the second widthwise one end edge 25a of the second linear portion 23 form an angle θ (0<θ<1 deg, preferably0.01 deg 0<0.95 deg, more preferably 0.05 deg≤θ≤0.95 deg).

The connection portion 31 is disposed between the first linear portion22 and the second linear portion 23 so as to connect them. The front endedge of the connection portion 31 is continuous with the rear end edgeof the first linear portion 22, and the rear end edge of the connectionportion 31 is continuous with the front end edge of the second linearportion 23.

The connection portion 31 includes a first side 32, second side 33,third side 34, and fourth side 35.

The first side 32 is formed so as to extend from the first widthwise oneend edge 24 a of the first linear portion 22 to further extend along thefirst linear direction. That is, the first side 32 extends from the oneend edge in the first linear direction (rear end edge) of the firstwidthwise one end edge 24 a toward the first linear direction one side(rear side). The first side 32 has a length D₁ of, for example, 100 μmor more, preferably 500 μm or more, and for example, 10000 μm or less,preferably 5000 μm or less.

The second side 33 is formed so as to extend from the second widthwiseother end edge 25 b of the second linear portion 23 further along thesecond linear direction. That is, the second side 33 extends from theother end edge in the second linear direction of the second widthwiseother end edge 25 b (front end edge) toward the other side in the secondlinear direction (front side). The second side 33 has a length D₂ of,for example, 100 μm or more, preferably 500 μm or more, and for example,10000 μm or less, preferably 5000 μm or less.

The third side 34 is formed so as to connect the end edge of the firstside 32 and the end edge of the second widthwise one end edge 25 a ofthe second linear portion 23, and extend along a first width direction(an example of first-crossing direction crossing the first lineardirection and the second linear direction). That is, the third side 34is a line that connects one end edge in the first linear direction (rearend edge) of the first side 32, with the other end edge in the secondlinear direction (front end edge) of the second widthwise one end edge25 a of the second linear portion 23. The third side 34 has a length D₃of, for example, 0.1 μm or more, preferably 0.5 μm or more, morepreferably 1 μm or more, and for example, 15 μm or less, preferably 10μm or less.

The fourth side 35 is formed so as to connect the end edge of the secondside 33 with the end edge of the first widthwise other end edge 24 b ofthe first linear portion 22, and extend along a second width direction(an example of second-crossing direction crossing the first lineardirection and the second linear direction). That is, the fourth side 35is a line that connects the other end edge in the second lineardirection (front end edge) of the second side 33 with one end edge ofthe first widthwise other end edge 24 b in the first linear direction(rear end edge) of the first linear portion 22. The fourth side 35 has alength D₄ of, for example, 0.1 μm or more, preferably 0.5 μm or more,more preferably 1 μm or more, and for example, 15 μm or less, preferably10 μm or less.

The second side 33 forms a first corner portion 36 with the fourth side35, and its angle is substantially the right angle (for example, 90±0.04deg, preferably 90±0.01 deg). The first side 32 forms a fourth cornerportion 37 with the third side 34, and its angle is substantially theright angle.

The connection portion 31 has a width broader than that of the firstlinear portion 22 and the second linear portion 23. That is, at theconnection portion 31, the first widths of the first side 32 and thesecond side 33 are longer than the width W of the first linear portion22.

The connection portion 31 satisfies the relationship of formula (1)below.

0<y ₁ <S  (1)

Y₁ represents a length from the first corner portion 36 to the firstwidthwise other end edge 24 b of the first linear portion 22 along thefirst width direction. That is, it represents the shortest distance ofthe first width between the first corner portion 36 and the first linearportion 22. Y₁ is a dislocation in the first width direction of thesecond linear portion 23 relative to the first linear portion 22. Y₁ is,for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably1 μm or more, and for example, 15 μm or less, preferably 10 μm or less.

S represents a length along the first width direction from the firstwidthwise other end edge 24 b of the first linear portion 22 in the wire12 a (one wire) to the first widthwise one end edge 24 a of the firstlinear portion 22 in the wire 12 b (the other wire). That is, S is awire interval between the wire 12 a and the wire 12 b. The other wire isa wire disposed adjacent with a space provided relative to one wire atthe other side in the first width direction. S is for example, 10 μm ormore, preferably 15 μm or more, and for example, 300 μm or less,preferably 150 μm or less.

The ratio of S to y₁ (S/y₁) is, for example, 2 or more, preferably 5 ormore, and for example, 100 or less, preferably 50 or less.

The connection portion 31 satisfies the relationship of formula (2)below.

D ₁×tan θ+y ₁ <S  (2)

At the connection portion 31, length D₁ of the first side 32 is the sameor longer than the first width W of the first linear portion 22. Thatis, the relationship of W≤D₁ (3) is satisfied.

Although the wire 12 a at the rightmost of the first region and thesecond region is described above, the same thing applies to the wires(12 b to 12 e) other than the wire 12 a. However, the wire 12 e havingno “the other wire” disposed at the other side in the first widthdirection, the formula (1) and formula (2) do not apply.

The same can be said to the wire 12 in the second region and the thirdregion as well. FIG. 4 shows a partial enlargement of the leftmost wire12 e as an example. In this case, the linear portion of the wire 12 inthe second region (in FIG. 4, front side) is regarded as the firstlinear portion 22, and the linear portion of the wire 12 in the thirdregion (in FIG. 4, rear side) is regarded as the second linear portion23.

As shown in FIG. 3 (relationship between the first region and the secondregion), with regard to the angle θ formed with the first lineardirection of one linear portion and the second linear direction ofanother linear portion (0<θ<1 deg), when the second linear directiontilts toward the left side relative to the first linear direction, thatis, when the circumferential direction from the first linear directionto the second linear direction is counterclockwise, the first widthwiseone end edge 24 a and the second widthwise one end edge 25 a arepositioned at the right side, and the first widthwise other end edge 24b and the second widthwise other end edge 25 b are positioned at theleft side. The other wires 12 (12 a to 12 e) are wires that arepositioned at left side relative to the one wires 12 (12 a to 12 e).

Meanwhile, as shown in FIG. 4 (relationship between the second regionand the third region), with regard to the angle θ formed with firstlinear direction of one linear portion and second linear direction ofanother linear portion (0<θ<1 deg), when the second linear directiontilts toward the right side relative to the first linear direction, thatis, when the circumferential direction from the first linear directionto the second linear direction is clockwise, the first widthwise one endedge 24 a and the second widthwise one end edge 25 a are positioned atthe left side, and the first widthwise other end edge 24 b and thesecond widthwise other end edge 25 b are positioned at the right side.The other wires 12 (12 a to 12 e) are wires 12 that are positioned atright side relative to the one wires 12 (12 a to 12 e).

The wire length of the wire portion 9 (front-rear direction length) is,for example, 600 mm or more, preferably 800 mm or more, and for example,5000 mm or less, preferably 3000 mm or less.

The insulating cover layer 4 is disposed, as shown in FIG. 1B, on theconductive pattern 3. To be specific, the insulating cover layer 4 isdisposed at the upper face of the insulating base layer 2 so as to coverthe upper face and the side face of the conductive pattern 3. Theinsulating cover layer 4 is formed so as to allow the electroniccomponent-mount portion 6, electronic component terminal portion 7, andexternal component terminal portion 8 to expose, and cover the wireportion 9. That is, the insulating cover layer 4 is formed into agenerally rectangular shape elongated in front-rear direction whenviewed from the top, from the rear side of the electronic componentterminal portion 7 to the front side of the external component terminalportion 8.

The insulating cover layer 4 is formed from the same insulating materialdescribed above for the insulating material of the insulating base layer2, and preferably, is formed from polyimide resin.

The insulating cover layer 4 has a thickness of, for example, 1 μm ormore, preferably 3 μm or more, and for example, 50 μm or less,preferably 30 μm or less.

<Production Method in First Embodiment>

A method for producing a wired circuit board 1 is described withreference to FIG. 5A to FIG. 7. The wired circuit board 1 is produced bysemiadditive method, and for example, includes a first step, in which aninsulating base layer 2 is prepared, a second step, in which aconductive pattern 3 is formed on the surface of the insulating baselayer 2, and a third step, in which an insulating cover layer 4 isformed on the surface of the conductive pattern 3.

(First Step)

In the first step, as shown in FIG. 5A, an insulating base layer 2elongated in front-rear direction is prepared.

When a plurality of the wired circuit boards 1 are formedsimultaneously, the insulating base layer 2 does not have to beelongated in the first step, and the insulating base layer 2 is trimmedto be elongated to have the contour of the wired circuit board 1 in thefinal step.

(Second Step)

In the second step, a conductive pattern 3 is formed on the surface ofthe insulating base layer 2. That is, the electronic component terminalportion 7, wire portion 9, and external component terminal portion 8 areformed on the upper face of the insulating base layer 2.

To be specific, the second step includes a step (1), in which the metalthin film 50 is formed on the surface of the insulating base layer 2, astep (2), in which the photo resist 51 is formed on the surface of themetal thin film 50, a step (3), in which the photo resist 51 is exposedto light with a photomask interposed therebetween, a step (4), in whichthe metal thin film 50 is exposed by development, a step (5), in whichthe conductive pattern 3 is formed by plating on the surface of themetal thin film 50 exposed, and a step (6), in which the metal thin film50 facing the remaining photo resist 51, and the remaining photo resist51 are removed.

Step (1)

As shown in FIG. 5B, the metal thin film 50 is formed on the surface ofthe insulating base layer 2.

To be specific, on the entire upper face of the insulating base layer 2,a metal thin film 50 (seed film) is formed. For the metal thin film 50,a metal material such as copper, chromium, nickel, and alloys thereofare used. The metal thin film is formed by thin film forming methodssuch as sputtering and plating. Preferably, the metal thin film 50 isformed by sputtering.

The metal thin film 50 has a thickness of, for example, 10 nm or more,and 300 nm or less.

Step (2)

As shown in FIG. 5C, a photo resist 51 is formed on the surface on themetal thin film 50.

The photo resist 51 is a positive type photo resist (positive photoresist). With the positive type photo resist, a portion where apredetermined amount or more of light is applied at the time of lightexposure is removed in the development thereafter, and meanwhile, aportion where the light is shielded (portion where a predeterminedamount or more of light was not applied, that is, portion whereapplication of less than a predetermined amount of light was allowed)remains in the development thereafter. The photo resist 51 includes, forexample, a dry film resist.

To be specific, the photo resist 51 is formed on the entire upper faceof the metal thin film 50. For example, the dry film resist is pressed(push against) by using for example, a flat plate.

The photo resist 51 has a thickness of, for example, 10 μm or more, and50 μm or less.

Step (3)

As shown in FIG. 5D, the photo resist 51 is exposed to light with aphotomask interposed therebetween.

For the photomask, a wire-photomask 40 and a terminal-photomask (notshown) are prepared.

As shown in FIG. 6, the wire-photomask 40 is formed into a generallyrectangular shape when viewed from the top.

The wire-photomask 40 has, for example, a light transmission portion 41and a shield portion 42.

The light transmission portion 41 is formed into a pattern of aplurality of (5) straight lines arranged in parallel corresponding to aplurality of (5) wires 12. To be specific, the light transmissionportion 41 includes a plurality of (5) light-transmitting regions havinga generally rectangular shape when viewed from the top extendinglinearly in front-rear direction, and the plurality oflight-transmitting regions have the same shape and arranged in parallelwith a space provided therebetween in left-right direction. The lighttransmission portion 41 is formed from, for example, a lighttransmitting material such as glass plate, or is formed with openings.

The shield portion 42 defines a portion other than the lighttransmission portion 41 in the wire-photomask 40, and is formed from ashield material such as metal plate.

The terminal-photomask (electronic component terminal-photomask,external component terminal-photomask) has a light transmission portioncorresponding to the electronic component terminal portion 7 or externalcomponent terminal portion 8.

Then, the photomask is disposed to face the surface of the photo resist51, and the photo resist 51 is exposed to light with a photomaskinterposed therebetween.

To be specific, the photomasks (wire-photomask 40, electronic componentend portion-photomask, and external component-photomask) are placed toface the surface of the upper side of the photo resist 51 with a spaceprovided therebetween, and the photo resist 51 is exposed to light.

To expose the photo resist 51 to light, light is applied to thephotomask from a light source placed above the photomask. Then, thelight applied to the shield portion 42 of the photomask is shielded bythe shield portion 42, and does not reach the photo resist 51.Meanwhile, the light applied to the light transmission portion 41 of thephotomask passes through the light transmission portion 41 and reachesthe photo resist 51.

As shown in FIG. 7, when the pattern of the wire portion 9 is exposed tolight through the wire-photomask 40, light exposure is conducted aplurality of times (n times) while shifting the wire-photomask 40 infront-rear direction one after another (for example, first lineardirection) so that the connection portion 31 is formed in each of thewires 12.

To be specific, the wire-photomask 40 is disposed so that in eachexposure process of the wire portion 9, the rear end of the linearpattern of the light transmission portion 41 in the wire-photomask 40(one end portion in first linear direction) in the previous exposureprocess (for example, m-th exposure process) overlaps with the front endof the linear pattern of the light transmission portion 41 in thewire-photomask 40 (the other end portion in second linear direction) inthe following exposure process (for example, m-th+1). That is, thewire-photomask 40 is disposed with shifting in front-rear direction sothat an overlapping region 43 is formed: in the overlapping region 43,the region corresponding to the position where the previouswire-photomask 40 is disposed overlaps the region where the followingwire-photomask 40 is disposed.

Furthermore, it is disposed so that the second linear direction relativeto the first linear direction, and the front end of the previouswire-photomask 40 relative to the rear end of the followingwire-photomask 40 are shifted a little in left-right direction (that is,in the range of length y₁).

Also, the wire-photomask 40 is disposed so that a predetermined angle θ(0<θ<1 deg) is formed with the linear pattern of the light transmissionportion 41 in the wire-photomask 40 of the previous light exposureprocess and the linear pattern of the light transmission portion 41 ofthe wire-photomask 40 in the following light exposure process.

In this manner, by conducting the following steps (development process,wire-forming process), in the overlapping region 43 where the previousphotomask overlaps with the following photomask, a connection portion 31with a narrower width than that of the linear pattern is formed at thefirst width. Also, the linear portion 21 corresponding to the linearpattern is formed with the adjacent two overlapping regions 43.

When the second linear direction tilts toward the left side relative tothe first linear direction, and when the circumferential direction fromthe first linear direction to the second linear direction iscounterclockwise in FIG. 7, the front end of the previous wire-photomask40 is disposed to shift a little to the left side (the other side in thefirst width direction) relative to the rear end of the followingwire-photomask 40 (that is, to achieve length y₁) (ref: FIG. 3).Meanwhile, when the second linear direction tilts toward the right siderelative to the first linear direction, that is, when thecircumferential direction from the first linear direction to the secondlinear direction is clockwise in FIG. 7, the front end of the previouswire-photomask 40 is disposed to shift a little to the right side (oneside in the first width direction) relative to the rear end of thefollowing wire-photomask 40 (that is, to achieve length y₁) (ref: FIG.4). Preferably, the light exposure time (n/2 times) is substantially thesame to achieve the positioning shown in FIG. 3 and the positioningshown in FIG. 4.

As necessary, for precise positioning of the photomask, an alignmentmark can be provided on the under layers such as the metal thin film 50and the insulating base layer 2, and the wire-photomask 40.

The wire portion 9 can be subjected to the light exposure by the lightexposure time n of, for example, 2 or more, preferably 3 or more, andfor example, 18 or less, preferably 12 or less.

Step (4)

As shown in FIG. 5E, the metal thin film 50 is exposed by development.

That is, the photo resist 51 facing the light transmission portion 41 isremoved.

To be specific, first, as necessary, the photo resist 51 after exposureto light is heated (heating after light exposure).

Then, the photo resist 51 is developed with a developer. This causes, inthe photo resist 51, the portion other than the light transmissionportion 41 (unexposed portion) to remain, and only the lighttransmission portion 41 (exposed portion) to be removed. That is, in thephoto resist 51, the opening 52 corresponding to the light transmissionportion 41 is formed. The opening 52 penetrates the photo resist 51 inthe thickness direction.

This causes the metal thin film corresponding to the light transmissionportion 41, that is, the metal thin film 50 facing the opening 52, to beexposed.

Step (5)

As shown in FIG. 5F, the conductive pattern 3 is formed on the surfaceof the exposed metal thin film 50 by plating.

To be specific, for example, electrolytic plating is conducted withelectricity supplied from the metal thin film 50.

At this time, the photo resist 51 is used as a plating resist. The metalthin film is used as an electric power supply layer.

In this manner, the conductive pattern 3 having the electronic componentterminal portion 7, wire portion 9 (a plurality of wires 12), andexternal component terminal portion 8 is formed.

Step (6)

The remaining photo resist 51 and the metal thin film 50 facing theremaining photo resist 51 are removed.

To be specific, first, as shown in FIG. 5G, the remaining photo resist51 is removed. For example, it is removed by wet etching.

Then, as shown in FIG. 5H, the metal thin film 50 facing the remainingphoto resist 51 is removed. To be specific, it is removed by peeling orwet etching.

(Third step)

In the third step, as shown in FIG. SI, the insulating cover layer 4 isformed on the surface of the wire portion 9.

To be specific, as shown in FIG. SI and FIG. 1B, the insulating coverlayer 4 is provided on the upper face of the wire portion 9 and theinsulating base layer 2 so that a pattern is formed so as to cover theupper face and side face of the wire portion 9 and to expose theelectronic component terminal portion 7 and the external componentterminal portion 8.

The wired circuit board 1 including the insulating base layer 2,conductive pattern 3, and insulating cover layer 4 is produced in thismanner.

Such a wired circuit board 1 is used, for example, for a wired circuitboard for catheters. To be specific, the electronic component 5 ismounted on the electronic component-mount portion 6, and the electroniccomponent 5 is electrically connected with the electronic componentterminal portion 7 by wire bonding. Afterwards, the wired circuit board1 is stored inside the catheter tube 60.

Examples of the electronic component 5 include those electroniccomponents necessary for examination and treatment, including a pressuresensor, temperature sensor, and heating element.

In this manner, as shown in FIG. 8A-FIG. 8B, a catheter 61 including theelectronic component 5, wired circuit board 1, and catheter tube 60 isobtained.

<Operation and Effect of First Embodiment>

In the wired circuit board 1, a plurality of wires 12 each includes (1)first linear portion 22 extending in the first linear direction, (2)second linear portion 23 having the same width as that of the firstlinear portion 22, disposed at one side in the first linear direction ofthe first linear portion 22, and extending in the second lineardirection so as to have a predetermined angle θ relative to the firstlinear portion 22, and (3) connection portion 31 disposed between thefirst linear portion 22 and the second linear portion 23, continuouswith these linear portions 22 and 23, and having a width broader thanthat of these linear portions 22 and 23. The connection portion 31includes (1) first side 32 extending from the first widthwise one endedge 24 a of the first linear portion 22 further along the first lineardirection, (2) second side 33 extending from the second widthwise otherend edge 25 b of the second linear portion 23 further along the secondlinear direction, (3) third side 34 connecting the first side 32 withthe second linear direction end edge of the second widthwise one endedge 25 a of the second linear portion 23, and extending along the firstwidth direction, and (4) fourth side 35 connecting the second side 33with the first linear direction end edge of the first widthwise otherend edge 24 b of the first linear portion 22, and extending along thesecond width direction. The relationships of 0<y₁<S and 0<θ<1 deg aresatisfied. Y₁ represents a length from the first corner portion 36 tothe first widthwise other end edge 24 b of the first linear portion 22along the first width direction. S represents a length from the firstwidthwise other end edge 24 b of the first linear portion 22 of one wire12 a to the first widthwise one end edge 24 a of the first linearportion 22 of the other wire 12 b along the first width (wire interval)in two wires 12 adjacent to each other.

Thus, length y₁ from the first corner portion 36 to the first linearportion 22, and length S (wire interval) from the first linear portion22 of one wire 12 a to the first linear portion 22 of the other wire 12b satisfy 0<y₁<S. That is, at the connection portion 31 between thefirst linear portion 22 and the second linear portion 23, the widthwisedislocation between the first linear portion 22 and the second linearportion 23 is shorter than the wire interval S. Also, the predeterminedangle θ satisfies θ<1 deg. That is, the angle formed with the firstlinear portion 22 and the second linear portion 23 is small. Thus, evenif the wire 12 a is formed to be elongated, linearity can be secured,short circuit between adjacent wires 12 b can be suppressed, andconnection reliability is excellent.

Also, the predetermined angle θ satisfies θ<0. That is, the angle formedwith the linear direction of the first linear portion 22 and the lineardirection of the second linear portion 23 is small. Thus, strictadjustment for the angle formed with the first linear portion 22 and thesecond linear portion 23 is unnecessary, and therefore productivity isexcellent.

In the wired circuit board, the length D₁ of the first side 32 and thelength S satisfy the relationship D₁×tan θ+y₁<S.

Thus, at the connection portion 31 between the first linear portion 22and the second linear portion 23, short circuit can be suppressed morereliably.

When the above-described formulas are not satisfied, that is, whenD₁×tan θ+y₁>S, the second widthwise other end edge 25 b of the secondlinear portion 23 of one wire 12 a makes contact with the fourth cornerportion 37 of the other wire 12 b. That is, a short circuit occursbetween the wire 12 a and the wire 12 b.

In the wired circuit board, the length D₁ and the first width W of thefirst linear portion 22 satisfy the relationship W≤D₁.

Thus, at the connection portion 31, the front-rear direction length ofthe connection portion 31 is sufficiently long. Therefore, the electricsignal easily flows in the front-rear direction (elongated direction)while widthwise flow is suppressed at the connection portion 31. Thus,propagation of electric signals is excellent.

The wired circuit board 1 includes the insulating base layer 2,conductive pattern 3 provided on the upper face of the insulating baselayer 2, and insulating cover layer 4 provided on the upper face of theconductive pattern 3, and the conductive pattern 3 includes the wire 12.

Thus, the insulating base layer 2, wire 12, and insulating base layer 2are disposed so as to make contact in this order. Thus, no adhesivelayer is necessary. As a result, moisture and heat resistance isexcellent, and the thickness can be decreased.

When the wire length of the wire portion 9 is 600 mm or more in thewired circuit board 1, it can be suitably used as a wired circuit boardfor catheters.

<Modified Example of the First Embodiment>

Modified example of the first embodiment is described next. In thefollowing figures, the members that are the same as the above-describedones are given the same reference numerals, and descriptions thereof areomitted.

(1) In the embodiment shown in FIG. 3, the front side is the firstlinear portion 22, and the rear side is the second linear portion 23,but as shown in FIG. 9, for example, the rear side can be the firstlinear portion 22, and the front side can be the second linear portion23. In the embodiment shown in FIG. 4, the front side is the firstlinear portion 22, and the rear side is the second linear portion 23,but for example, although not shown, the rear side can be the firstlinear portion 22, and the front side can be the second linear portion23.

(2) In the embodiment shown in FIG. 3, the angles of the first cornerportion 36 and fourth corner portion 37 are substantially right angle,but as shown in FIG. 10, for example, the angles for the first cornerportion 36 and fourth corner portion 37 can be an obtuse angle.

In the embodiment shown in FIG. 10, the angles for the first cornerportion 36 and fourth corner portion 37 are more than 90°, preferably100° or more, and for example, 160° or less, preferably 140° or less.

The third side 34 is formed so as to connect the end edge of the firstside 32 with the end edge of the second widthwise one end edge 25 a ofthe second linear portion 23, and to extend along the first-crossingdirection crossing the first linear direction and the second lineardirection.

The fourth side 35 is formed so as to connect the end edge of the secondside 33 with the end edge of the first widthwise other end edge 24 b ofthe first linear portion 22, and to extend along the second-crossingdirection crossing the first linear direction and the second lineardirection.

In this embodiment as well, preferably, as an approximate value, therelationship of formula (2) and (3) is satisfied.

In the embodiment shown in FIG. 10, it is produced by adjusting lightexposure angle and amount at the front-rear direction end portion of thelight transmission portion 41 in the light exposure process shown inFIG. 5D.

(3) In the embodiment shown in FIG. 2, the plurality of linear portions21 (21 a, 21 b, 21 c, 21 d, 21 e) each has the same first width W, butfor example, although not shown, the plurality of linear portions 21 (21a, 21 b, 21 c, 21 d, 21 e) each can have a different first width W.

In this embodiment, in step (3), light exposure is conducted by using awire-photomask 40 (not shown) having a different length in the pluralityof linear pattern left-right direction length of the light transmissionportion 41.

(4) In the embodiment shown in FIG. 2, a plurality of wire intervals Sare all the same length, but for example, although not shown, theplurality of wire intervals S can be different.

In this embodiment, in step (3), light exposure is conducted by using awire-photomask 40 (not shown) having a different left-right directioninterval in a plurality of linear patterns adjacent to each other.

(5) In the embodiment shown in shown in FIG. 1A, a support substrate isnot included, but for example, although not shown, a support substratesuch as a metal plate can be included at a portion of the lower face(the other side in thickness direction) of the insulating base layer 2.To be specific, for example, the support substrate is disposed at thelower face of the insulating base layer 2 corresponding the electroniccomponent-mount portion 6 and the electronic component terminal portion7.

(6) In the light exposure process and development process of theembodiment shown in the FIG. 5D and FIG. 5E, the photomask is used forlight exposure, and the photo resist 51 is developed in all theformation of the conductive pattern 3, but for example, although notshown, the photo resist 51 can be developed by using a laser directimaging in the formation of a portion of the conductive pattern 3.

To be specific, for example, the electronic component terminal portion 7and/or external component terminal portion 8 can be formed by developingthe photo resist by using a laser direct imaging. A portion of the wireportion 9 (for example, a portion of the plurality of regions) can beformed by developing the photo resist 51 using the laser direct imaging.

(7) In FIGS. 2 and 7, in all of the plurality of the parallelly arrangedlinear portions 20, the linear portions 21 of two adjacent parallellyarranged linear portions 20 form an angle θ (0<θ<1 deg), but forexample, although not shown, in a portion of the parallelly arrangedlinear portions 20, the angle formed by the linear portions 21 of thetwo adjacent parallelly arranged linear portions 20 can be 0 deg, or itcan be more than 1 deg.

Preferably, the region where the linear portions 21 of the two adjacentparallelly arranged linear portions 21 form the angle θ (0<θ<1 deg) ispreferably 50% or more, more preferably 80% or more, even morepreferably 100%, relative to the entire region of the two adjacentparallelly arranged linear portions 21.

In the embodiments of these (1) to (7) as well, the same operation andeffect of the embodiments in the above-described FIG. 1A to FIG. 7 canbe achieved.

Second Embodiment

With reference to FIG. 11 to FIG. 14, the wired circuit board 1 as thesecond embodiment of the wired circuit board of the present invention isdescribed. In the following figures, the members that are the same asthe above-described ones are given the same reference numerals, anddescriptions thereof are omitted.

As shown in FIG. 11, the wired circuit board 1 is a flexible wiredcircuit board (FPC) elongated in front-rear direction, and is formedinto a flat plate shape extending in (sheet shape) front-rear direction.The wired circuit board 1 includes, as shown in FIG. 1B, an insulatingbase layer 2, conductive pattern 3 formed on the insulating base layer2, and insulating cover layer 4 formed on the conductive pattern 3.

The conductive pattern 3 is formed on the upper face of the insulatingbase layer 2. The conductive pattern 3 includes, as shown in FIG. 11, anelectronic component terminal portion 7, external component terminalportion 8, and wire portion 9.

The electronic component terminal portion 7 includes a plurality of (4)electronic component terminals 10.

The external component terminal portion 8 includes a plurality of (4)external component terminals 11.

The wire portion 9 is disposed between the electronic component terminalportion 7 and the external component terminal portion 8 so as to connectthem. The wire portion 9 includes a plurality of (4) wires 12 (12 a, 12b, 12 c, 12 d) in correspondence with the plurality of (4) electroniccomponent terminal portions 7 and a plurality of (4) external componentterminal portions 8.

The plurality of wires 12 are formed so as to extend in front-reardirection. The wire 12 is integrally formed with the electroniccomponent terminal 10 and the external component terminal 11 so that thefront end edge thereof is continuous with the rear end edge of theelectronic component terminal 10, and their end edge is continuous withthe front end edge of the external component terminal 11.

The wire portion 9 includes a pattern produced by conducting exposure tolight and development a plural times using a wire-photomask 40 in theproduction method as described later with reference to FIG. 12. That is,in the wire portion 9, a single pattern region in correspondence with apattern of one set of exposure to light and development (first region,second region, third region, ⋅ ⋅ ⋅ individually) of the wire-photomask40 continues a plural times in front-rear direction, with a partialoverlapping at both ends in front-rear direction. To be specific, thewire portion 9 includes a parallelly arranged linear portion 20corresponding to the center portion in front-rear direction of theshield portion 42, and a parallelly arranged connection portion 30 ofthe overlapping region 43 of the wire-photomask 40. The wire portion 9is formed from a plurality of parallelly arranged linear portions 20 anda plurality of parallelly arranged connection portions 30. That is, thewire portion 9 is formed so that the parallelly arranged linear portion20 and the parallelly arranged connection portion 30 are alternatelycontinuous in front-rear direction.

As shown in FIG. 12, the parallelly arranged linear portion 20 eachincludes a plurality of (4) linear portions 21 (21 a, 21 b, 21 c, 21 d)disposed in left-right direction with equal interval therebetween. Theplurality of linear portions 21 are formed into a linear pattern eachhaving a predetermined width and extending linearly. The plurality oflinear portions 21 (21 a, 21 b, 21 c, 21 d) have substantially the sameshape.

The parallelly arranged connection portion 30 each includes a pluralityof (4) connection portions 31 (31 a, 31 b, 31 c, 31 d) disposed inleft-right direction with equal interval therebetween. The plurality ofconnection portions 31 have substantially the same shape, and its widthis formed to be narrower than that of the linear portion 21 (21 a, 21 b,21 c, 21 d).

Next, description is given with reference to FIG. 13 as to one linearportion (hereinafter referred to as first linear portion 22), oneconnection portion 31 continuous to the rear side of the first linearportion 22, and another linear portion continuous to the rear side ofthe one connection portion 31 (hereinafter referred to as second linearportion 23), using the wire 12 (12 a) at the rightmost in the firstregion (m-th region) and the second region (m-th+1 region) as anexample.

The first linear portion 22 is formed into a linear pattern extendinglinearly in the first linear direction. The width W of the first linearportion 22 (first width) is substantially the same from the front end tothe rear end of the first linear portion 22. The first linear portion 22includes a fourth side 35 described later.

The first linear portion 22 has a width W of, for example, 10 μm ormore, preferably 15 μm or more, and for example, 300 μm or less,preferably 150 μm or less.

The second linear portion 23 is formed into a linear pattern extendinglinearly in the second linear direction. The width of the second linearportion 23 (second width) is the same as the width W of the first linearportion 22. The width of the second linear portion 23 is substantiallythe same from the front end to the rear end of the second linear portion23. The second linear portion 23 has substantially the same shape asthat of the first linear portion 22, except for the direction of theextension of the second linear portion 23. The second linear portion 23includes a third side 34 described later.

The first linear direction and the second linear direction form an angleθ (0<θ<1 deg, preferably 0.01 deg≤θ≤0.95 deg, more preferably 0.05deg≤θ≤0.95 deg). To be specific, the first widthwise one end edge 24 aof the first linear portion 22 and the second widthwise one end edge 25a of the second linear portion 23 form an angle θ (0<θ<1 deg, preferably0.01 deg≤θ≤0.95 deg, more preferably 0.05 deg≤θ≤0.95 deg).

The connection portion 31 is disposed between the first linear portion22 and the second linear portion 23 so as to connect them. The front endedge of the connection portion 31 is continuous with the rear end edgeof the first linear portion 22, and the rear end edge of the connectionportion 31 is continuous with the front end edge of the second linearportion 23.

The connection portion 31 includes a first side 32 and second side 33.

The first side 32 is formed so that it extends from the first widthwiseone end edge 24 a of the first linear portion 22 to further extend alongthe first linear direction. That is, the first side 32 extends from theone end edge in the first linear direction (rear end edge) of the firstwidthwise one end edge 24 a toward the first linear direction one side(rear side). The length D of the first side 32 is the same as that inthe first embodiment.

The second side 33 is formed so as to extend from the second widthwiseother end edge 25 b of the second linear portion 23 further along thesecond linear direction. That is, the second side 33 extends from theother end edge in the second linear direction of the second widthwiseother end edge 25 b (front end edge) toward the second linear directionthe other side (front side). The length D₂ of the second side 33 is thesame as that in the first embodiment.

The third side 34 is formed so as connect the end edge of the first side32 and the end edge of the second widthwise one end edge 25 a of thesecond linear portion 23, and further extend along the first widthdirection (an example of first-crossing direction crossing the firstlinear direction and the second linear direction). That is, the thirdside 34 is a line that connects one end edge in the first lineardirection (rear end edge) of the first side 32 with the other end edgein the second linear direction (front end edge) of the second widthwiseone end edge 25 a. The length D₃ of the third side 34 is the same asthat in the first embodiment.

The fourth side 35 is formed so as to connect the end edge of the secondside 33 with the end edge of the first widthwise other end edge 24 b ofthe first linear portion 22, and extend along the second width direction(an example of second-crossing direction crossing the first lineardirection and the second linear direction). That is, the fourth side 35is a line that connects the other end edge in the second lineardirection (front end edge) of the second side 33 with one end edge ofthe first widthwise other end edge 24 b in the first linear direction(rear end edge). The length D₄ of the fourth side 35 is the same as thatin the first embodiment.

The second widthwise one end edge 25 a of the second linear portionforms a second corner portion 38 with the third side 34 and its angle is90°+0. The second side 33 forms a third corner portion 39 with thefourth side 35, and its angle is substantially the right angle. Thefifth corner portion 45 formed with the first side 32 and the third side34 is substantially right angle.

The connection portion 31 has a width narrower than that of the firstlinear portion 22 and the second linear portion 23. That is, at theconnection portion 31, the first width of the first side 32 and thesecond side 33 is narrower than the width W of the first linear portion22.

The second linear portion 23 satisfies the relationship of formula (4)below.

0<y ₂ <W  (4)

Y₂ represents a length from the second corner portion 38 to the firstside 32 along the first width direction. That is, it represents theshortest distance of the first width between the second corner portion38 and the first side 32. Y₂ is a dislocation in the first widthdirection of the second linear portion 23 relative to the first linearportion 22.

Y₂ is, for example, 0.1 μm or more, preferably 0.5 μm or more, morepreferably 1 μm or more, and for example, 15 μm or less, preferably 10μm or less.

W represents the first width of the first linear portion 22, and is thesame as that in the first embodiment.

The ratio of W to y₂ (W/y₂) is, for example, 2 or more, preferably 5 ormore, and for example, 100 or less, preferably 50 or less.

The first linear portion 22 satisfies the relationship of formula (5)below.

D ₁×tan θ+y ₂ ′<W  (5)

Y₂′ represents a length from the third corner portion 39 to the firstwidthwise other end edge 24 b of the first linear portion 22 along thefirst width direction. That is, it represents the shortest distance ofthe first width between the third corner portion 39 and the firstwidthwise other end edge 24 b. Y₂′ is also a dislocation in the firstwidth direction of the second linear portion 23 relative to the firstlinear portion 22.

Y₂′ is, for example, 0.1 μm or more, preferably 0.5 μm or more, morepreferably 1 μm or more, and for example, 15 μm or less, preferably 10μm or less.

Although the wire 12 a at the rightmost of the first region and thesecond region is described above, the same thing applies to the wires(12 b to 12 d) other than the wire 12 a.

The same can be said to the wire 12 in the second region and the thirdregion as well. FIG. 14 shows a partial enlargement of the leftmost wire12 as an example. In this case, the linear portion of the wire 12 in thesecond region (in FIG. 14, front side) is regarded as the first linearportion 22, and the linear portion of the wire 12 in the third region(in FIG. 14, rear side) is regarded as the second linear portion 23.

As shown in FIG. 13 (relationship between the first region and thesecond region), with regard to the angle θ formed with the first lineardirection of one linear portion and the second linear direction ofanother linear portion (0<θ<1 deg), when the second linear directiontilts toward the left side relative to the first linear direction, thatis, the circumferential direction from the first linear direction towardthe second linear direction is counterclockwise, the first widthwise oneend edge 24 a and the second widthwise one end edge 25 a are positionedat the left side, and the first widthwise other end edge 24 b and thesecond widthwise other end edge 25 b are positioned at the right side.

Meanwhile, as shown in FIG. 14 (relationship between the second regionand the third region), with regard to the angle θ formed with the firstlinear direction of one linear portion and the second linear directionof another linear portion (0<θ<1 deg), when the second linear directiontilts toward the right side relative to the first linear direction, thatis, when the circumferential direction from the first linear directiontoward the second linear direction is clockwise, the first widthwise oneend edge 24 a and the second widthwise one end edge 25 a are positionedat the right side, and the first widthwise other end edge 24 b and thesecond widthwise other end edge 25 b are positioned at the left side.

The wire length of the wire portion 9 is the same as that in the firstembodiment.

<Production Method in Second Embodiment>

A method for producing a wired circuit board 1 is described withreference to FIG. 15 and FIG. 12. The wired circuit board 1 is producedby semiadditive method, and for example, includes a first step, in whichan insulating base layer 2 is prepared, a second step, in which aconductive pattern 3 is formed on the surface of the insulating baselayer 2, and a third step, in which an insulating cover layer 4 isformed on the surface of the conductive pattern 3.

(First Step)

In the first step, as shown in FIG. 15A, an insulating base layer 2elongated in front-rear direction is prepared. To be specific, it isprepared in the same manner as in the first embodiment.

(Second Step)

In the second step, a conductive pattern 3 is formed on the surface ofthe insulating base layer 2. That is, the electronic component terminalportion 7, wire portion 9, and external component terminal portion 8 areformed on the upper face of the insulating base layer 2.

To be specific, the second step includes a step (1), in which the metalthin film 50 is formed on the surface of the insulating base layer 2, astep (2), in which the photo resist 51 is formed on the surface of themetal thin film 50, a step (3), in which the photo resist 51 is exposedto light with a photomask interposed therebetween, a step (4), in whichthe metal thin film 50 is exposed by development, a step (5), in which aconductive pattern 3 is formed by plating on the surface of the metalthin film 50, and a step (6), in which the metal thin film 50 facing theremaining photo resist 51, and the remaining photo resist 51 areremoved.

Step (1)

As shown in FIG. 15B, the metal thin film 50 is formed on the surface ofthe insulating base layer 2. To be specific, it is prepared in the samemanner as in the first embodiment.

Step (2)

As shown in FIG. 15C, a photo resist 51 is formed on the surface of themetal thin film 50.

The photo resist 51 is a negative type photo resist (negative photoresist). With the negative type photo resist, a portion where shielded(portion where a predetermined amount or more of light was not applied,that is, portion where application of less than a predetermined amountof light was allowed) at the time of light exposure is removed in thedevelopment thereafter, and meanwhile, a portion where a predeterminedamount or more of light was applied at the time of light exposureremains in the development thereafter. The photo resist 51 include, forexample, dry film resist.

To be specific, it is the same as that in the first embodiment exceptthat a negative type photo resist is used.

Step (3)

As shown in FIG. 15D, the photo resist 51 is exposed to light with aphotomask interposed therebetween.

For the photomask, a wire-photomask 40 and a terminal-photomask (notshown) are prepared.

As shown in FIG. 16, the wire-photomask 40 is formed into a generallyrectangular when viewed from the top.

The wire-photomask 40 has, for example, a shield portion 42 and a lighttransmission portion 41.

The shield portion 42 is formed into a pattern of a plurality of (4)straight lines arranged in parallel.

The shield portion 42 is formed into a pattern of a plurality of (4)straight lines arranged in parallel corresponding to a plurality of (4)wires 12. To be specific, the shield portion 42 includes a plurality of(4) shield regions having a generally rectangular shape when viewed fromthe top extending linearly in front-rear direction, and the plurality ofshield regions have the same shape and arranged in parallel with a spaceprovided therebetween in left-right direction. The shield portion 42 isformed from a light shielding material such as metal plate.

The light transmission portion 41 defines a portion other than theshield portion 42 in the wire-photomask 40, and for example, is formedfrom a light transmitting material such as glass plate.

Then, the photomask is disposed to face the surface of the photo resist51, and the photo resist 51 is exposed to light with a photomaskinterposed therebetween. To be specific, it is prepared in the samemanner as in the first embodiment.

As shown in FIG. 12, when the pattern of the wire portion 9 is exposedto light through the wire-photomask 40, light exposure is conducted aplurality of times (n times) while shifting the wire-photomask 40 infront-rear direction (for example, first linear direction) one afteranother so that the connection portion 31 is formed in each of the wires12. To be specific, it is prepared in the same manner as in the firstembodiment.

In this manner, by conducting the following steps (development process,wire-forming process), in the region (overlapping region 43) where theprevious photomask overlaps with the following photomask, a connectionportion 31 with a narrower width than that of the linear pattern isformed at the first width. Also, the linear portion 21 corresponding tothe linear pattern is formed with the adjacent two overlapping regions43.

It is disposed so that the second linear direction relative to the firstlinear direction, and the front end of the previous wire-photomask 40relative to the rear end of the following wire-photomask 40 shift inleft-right direction to a small degree (that is, in the range of lengthy₂ or length y₂′). In particular, when the second linear direction tiltstoward the left side relative to the first linear direction, and whenthe circumferential direction from the first linear direction to thesecond linear direction is counterclockwise in FIG. 12, preferably, thefront end of the previous wire-photomask 40 is disposed to shift alittle to the left side (the other side in the first width direction)relative to the rear end of the following wire-photomask 40 (that is, toachieve length y₂ or length y₂′) (ref: FIG. 13). Meanwhile, when ittilts to the right side, the circumferential direction from the firstlinear direction to the second linear direction is clockwise in FIG. 12,preferably, the front end of the previous wire-photomask 40 is disposedto shift a little to the right side (one side in the first widthdirection) relative to the rear end of the following wire-photomask 40(that is, to achieve length y₂ or length y₂′) (ref: FIG. 14).Preferably, the light exposure time (n/2 times) is substantially thesame to achieve the positioning shown in FIG. 13 and FIG. 14.

The light exposure time n of the wire portion 9 is the same as that inthe first embodiment.

Step (4)

As shown in FIG. 15E, the metal thin film 50 is exposed by development.

That is, the photo resist 51 facing the shield portion 42 is removed.

To be specific, first, as necessary, the photo resist 51 after exposureto light is heated (heating after light exposure).

Then, the photo resist 51 is developed with a developer. This causes, inthe photo resist 51, the portion other than the shield portion 42(exposed portion) to remain, and only the shield portion 42 (unexposedportion) to be removed. That is, in the photo resist 51, the opening 52corresponding to the shield portion 42 is formed. The opening 52penetrates the photo resist 51 in the thickness direction.

This causes the metal thin film corresponding to the shield portion 42,that is, the metal thin film 50 facing the opening 52 is exposed.

Step (5)

As shown in FIG. 15F, the conductive pattern 3 is formed on the surfaceof the exposed metal thin film 50 by plating. To be specific, it isprepared in the same manner as in the first embodiment.

Step (6) As shown in FIG. 15G and FIG. 15H, the remaining photo resist51 and the metal thin film 50 facing the remaining photo resist 51 areremoved. To be specific, it is prepared in the same manner as in thefirst embodiment.

(Third step)

In the third step, as shown in FIG. 15I, the insulating cover layer 4 isformed on the surface of the wire portion 9. To be specific, it isprepared in the same manner as in the first embodiment.

The wired circuit board 1 including the insulating base layer 2,conductive pattern 3, and insulating cover layer 4 is produced in thismanner.

The wired circuit board 1 is suitably used, for example, as a wiredcircuit board for catheters, as shown in FIG. 8A-FIG. 8B.

<Operation and Effect of Second Embodiment>

In the wired circuit board, a plurality of wires each includes (1) firstlinear portion 22 extending in the first linear direction, (2) secondlinear portion 23 having the same width as that of the first linearportion 22, disposed at one side in the first linear direction of thefirst linear portion 22, and extending in the second linear direction soas to have a predetermined angle θ relative to the first linear portion22, and (3) connection portion 31 disposed between the first linearportion 22 and the second linear portion 23, continuous with theselinear portions 22 and 23, and having a width broader than that of theselinear portions 22 and 23. The connection portion 31 includes (1) firstside 32 extending from the first widthwise one end edge 24 a of thefirst linear portion 22 further along the first linear direction, and(2) second side 33 extending from the second widthwise other end edge 25b of the second linear portion 23 further along the second lineardirection. The second linear portion 23 includes (3) third side 34connecting the first side 32 with the second linear direction end edgeof the second widthwise one end edge 25 a of the second linear portion23, and extending along the first width direction. The first linearportion 22 includes (4) fourth side 35 connecting the second side 33with the first linear direction end edge of the first widthwise otherend edge 24 b of the first linear portion 22, and extending along thesecond width direction. The relationship of 0<y₂<W and 0<θ<1 deg aresatisfied. Y₂ represents a length from the second corner portion 38 tothe first side 32 along the first width direction. W represents thefirst width W of the first linear portion 22.

Thus, the length y₂ from the second corner portion 38 to the first side32, and the first width W of the first linear portion 22 satisfy therelationship of 0<y₂<W. That is, at the connection portion 31 betweenthe first linear portion 22 and the second linear portion 23, widthwisedislocation between the first linear portion 22 and the second linearportion 23 is shorter than the width W of the first linear portion 22.Also, the predetermined angle θ satisfies θ<1 deg. That is, the angleformed with the first linear portion 22 and the second linear portion 23is small Thus, even if the wire 12 a is formed into an elongated form,linearity can be secured, and in the wire 12 continuous in thefront-rear direction, disconnection at the connection portion 31 can besuppressed, and connection reliability is excellent.

Also, the predetermined angle θ satisfies θ<0. That is, the angle formedwith the linear direction of the first linear portion 22 and the lineardirection of the second linear portion 23 is small. Thus, strictadjustment for the angle formed with the first linear portion 22 and thesecond linear portion 23 is unnecessary, and therefore productivity isexcellent.

In the wired circuit board, the relationship of formula D₁×tan θ+y₂′<Wis satisfied. Y₂′ represents a length from the third corner portion 39to the first widthwise other end edge 24 b of the first linear portion22 along the first width direction.

Thus, at the connection portion 31 between the first linear portion 22and the second linear portion 23, disconnection can be suppressed evenmore reliably.

When the above-described formula is not satisfied, that is, when D₁×tanθ+y₂′≥W, the fifth corner portion 45 (ref: FIG. 13) formed with thefirst side 32 and the third side 34 makes contact with the secondwidthwise other end edge 25 b of the second linear portion 23. That is,the connection between the connection portion 31 and the second linearportion 23 is cut.

The wired circuit board 1 includes the insulating base layer 2,conductive pattern 3 provided on the upper face of the insulating baselayer 2, and insulating cover layer 4 provided on the upper face of theconductive pattern 3, and the conductive pattern 3 includes the wire 12.

Thus, the insulating base layer 2, wire 12, and insulating base layer 2are disposed so as to make contact in this order. Thus, no adhesivelayer is necessary. As a result, moisture and heat resistance isexcellent, and the thickness can be decreased.

When the wire length of the wire portion 9 is 600 mm or more in thewired circuit board 1, it can be suitably used as a wired circuit boardfor catheters.

<Modified Example of the Second Embodiment>

Modified example of the second embodiment is described next. In thefollowing figures, the members that are the same as the above-describedones are given the same reference numerals, and descriptions thereof areomitted.

(1) In the embodiment shown in FIG. 13, the front side is the firstlinear portion 22, and the rear side is the second linear portion 23,but for example, as shown in FIG. 17, the rear side can be first linearportion 22, and the front side can be the second linear portion 23. Inthe embodiment shown in FIG. 14, the front side is the first linearportion 22, and the rear side is the second linear portion 23, but forexample, although not shown, the rear side can be the first linearportion 22, and the front side can be the second linear portion 23.

(2) In the embodiment shown in FIG. 13, the angle of the third cornerportion 39 and the fifth corner portion 45 is substantially right angle,but for example, as shown in FIG. 18, the angle of the third cornerportion 39 and the fifth corner portion 45 can be an obtuse angle.

In the embodiment shown in FIG. 18, the angle of the third cornerportion 39 and the fifth corner portion 45 is more than 90°, preferably100° or more, and for example, 160° or less, preferably 140° or less.

The third side 34 is formed so as to connect the end edge of the firstside 32 with the end edge of the second widthwise one end edge 25 a ofthe second linear portion 23, and to extend along the first-crossingdirection crossing the first linear direction and the second lineardirection.

The fourth side 35 is formed so as to connect the end edge of the secondside 33 with the end edge of the first widthwise other end edge 24 b ofthe first linear portion 22, and to extend along the second-crossingdirection crossing the first linear direction and the second lineardirection.

In this embodiment as well, preferably, as an approximate value, therelationship of formula (5) is satisfied.

In the embodiment shown in FIG. 18, it is produced by adjusting lightexposure angle and amount at the front-rear direction end portion of thelight transmission portion 41 in the light exposure process shown inFIG. 15D.

(3) In the embodiment shown in FIG. 12, the plurality of linear portions21 (21 a, 21 b, 21 c, 21 d) each has the same first width W, but forexample, although not shown, the plurality of linear portions 21 (21 a,21 b, 21 c, 21 d) each can have a different first width W.

In this embodiment, in step (3), light exposure is conducted by using awire-photomask 40 (not shown) having a different left-right directionlength in the pattern of plurality of straight lines in the shieldportion 42.

(4) In the embodiment shown in FIG. 12, a plurality of wire intervals Sare all the same length, but for example, although not shown, theplurality of wire intervals S can be different.

In this embodiment, in step (3), light exposure is conducted by using awire-photomask 40 (not shown) having a different left-right directioninterval in the pattern of plurality of straight lines in the lighttransmission portion 41.

(5) In the embodiment shown in FIG. 11, a support substrate is notincluded, but for example, although not shown, a support substrate suchas a metal plate can be included at a portion of the lower face (theother side in thickness direction) of the insulating base layer 2. To bespecific, it is prepared in the same manner as in the modified exampleof the first embodiment.

(6) In the light exposure process and development process of theembodiment shown in FIG. 15D and FIG. 15E, in all the formation of theconductive pattern 3, the photomask is used for light exposure, and thephoto resist 51 is developed, but for example, although not shown, byusing a laser direct imaging in the formation of a portion of theconductive pattern 3, the photo resist 51 can be developed. To bespecific, it is prepared in the same manner as in the modified exampleof the first embodiment.

(7) In FIG. 12, in all of the plurality of the parallelly arrangedlinear portions 20, the linear portion 21 of two adjacent parallellyarranged linear portion 20 forms an angle θ (0<θ<1 deg), but forexample, although not shown, in a portion of the parallelly arrangedlinear portion 20, the angle formed by the linear portion 21 of the twoadjacent parallelly arranged linear portion 20 can be 0 deg, or it canbe more than 1 deg.

Preferably, the region where the linear portions 21 of the two adjacentparallelly arranged linear portions 21 form the angle θ (0<θ<1 deg) ispreferably 50% or more, more preferably 80% or more, even morepreferably 100% relative to the entire region of the two adjacentparallel arranged linear portions 21.

In the embodiments of these (1) to (7) as well, the same operation andeffect of the embodiments in the above-described FIG. 11 to FIG. 15 canbe achieved.

While the illustrative embodiments of the present invention are providedin the above description, such is for illustrative purpose only and itis not to be construed as limiting in any manner Modification andvariation of the present invention that will be obvious to those skilledin the art is to be covered by the following claims.

INDUSTRIAL APPLICABILITY

The wired circuit board of the present invention can be suitably usedfor various industrial products, and for example, can be suitably usedfor a wired circuit board for catheters.

DESCRIPTION OF REFERENCE NUMERALS

-   1 wired circuit board-   2 insulating base layer-   3 conductive pattern-   4 insulating cover layer-   9 wire portion-   12 wire-   21 linear portion-   31 connection portion-   22 first linear portion-   23 second linear portion-   24 a first widthwise one end edge-   24 b first widthwise other end edge-   25 a second widthwise one end edge-   25 b second widthwise other end edge-   32 first side-   33 second side-   34 third side-   35 fourth side-   36 first corner portion-   38 second corner portion-   39 third corner portion-   40 wire-photomask-   41 light transmission portion-   42 shield portion-   43 overlapping region-   50 metal thin film-   51 photo resist

1. An elongated wired circuit board including a plurality of wiresarranged in parallel, wherein the plurality of wires each includes afirst linear portion extending in a first linear direction, a secondlinear portion having the same width as that of the first linearportion, disposed at one side in the first linear direction of the firstlinear portion, and extending in a second linear direction so as to havea predetermined angle θ relative to the first linear portion, and aconnection portion disposed between the first linear portion and thesecond linear portion, being continuous with the first linear portionand the second linear portion, and having a width broader than that ofthe first linear portion, the connection portion includes a first sidefurther extending from a first widthwise one end edge orthogonal to thefirst linear direction of the first linear portion along the firstlinear direction, a second side further extending from the secondwidthwise other end edge orthogonal to the second linear direction ofthe second linear portion along the second linear direction, a thirdside connecting the first side with the second widthwise one end edge ofthe second linear portion and extending along the first-crossingdirection crossing the first linear direction and the second lineardirection, and a fourth side connecting the second side with the firstwidthwise other end edge of the first linear portion, and extendingalong a second-crossing direction crossing the first linear directionand the second linear direction, length y₁ and length S satisfy therelationship of 0<y₁<S, the length y₁ extending from a first cornerportion formed with the second side and the fourth side along the firstwidth direction and reaching the first widthwise other end edge of thefirst linear portion, and length S extending from the first widthwiseother end edge of the first linear portion of one wire to a firstwidthwise one end edge of the first linear portion of the other wirealong the first width direction in two wires adjacent to each other, andthe predetermined angle θ satisfies the relationship of0<θ<1 deg.
 2. The wired circuit board according to claim 1, wherein thelength D₁ of the first side and the length S satisfy the relationship ofD ₁×tan θ+y ₁ <S.
 3. The wired circuit board according to claim 1,wherein the length D₁ and a length W of the first width direction of thefirst linear portion satisfy the relationship ofW≤D ₁.